Restraining devices are frequently used in connection with animal husbandry activities, especially those which deal with the treatment of livestock. The most common restraining devices known in the prior art are used in connection with a doorway, a gate, or a chute and secure the head of an animal. Such devices are commonly referred to as head gates and generally require manual operation by one person while another person urges the animal into the engagement area. Also, several of the prior art devices employ a self-locking structure which is operated by the movement of the animal into the device.
Typical of the prior art head gates is shown in U.S. Pat. No. 3,513,812. The device shown therein is a self locking livestock head gate consisting of a stanchion having closely spaced head locking members pivoted for forward, tilting, converging movement caused by movement of an animal. Various other elements of the structure prevent the animal from withdrawing therefrom once engagement is obtained.
U.S. Pat. No. 3,623,456 shows another head gate which employs a pair of animal neck engaging members supported on a main frame for simultaneous vertical movement and a lateral movement toward and away from each other within the transverse confines of a main frame.